A typical three-transistor (3T) pixel of an optoelectronic image sensor suffers from high reset noise, which limits the signal-to-noise ratio (SNR) and dynamic range of the pixel. A common noise component in these image sensors is kTC noise, wherein C is the switch capacitance of the field-effect transistor (FET) gate, k is Boltzmann's constant, and T is the absolute temperature (measured in ° K).
Active pixel reset is a known method for suppressing kTC noise in a 3T pixel. For this purpose, a dedicated operational amplifier is typically coupled to each column adjacent to the pixel array. Designs of this sort are described, for example, by B. Fowler et al., “Low Noise Readout using Active Reset for CMOS APS,” Proc. SPIE 3965, Sensors and Camera Systems for Scientific, Industrial, and Digital Photography Applications, p. 126, SPIE Press, Bellingham, Wash., 2000, as well as M. Ishii et al., “An Ultra-low Noise Photoconductive Film Image Sensor with a High-speed Column Feedback Amplifier Noise Canceller,” IEEE 2013 SYMPOSIUM ON VLSI CIRCUITS, pp. C8-C9, June 2013, IEEE, New York, N.Y. A distributed feedback amplifier for kTC noise suppression in 3T pixels was proposed by L. Kozlowski et al. in “Pixel Noise Suppression via SoC Management of Tapered Reset in a 1920×1080 CMOS Image Sensor,” IEEE Journal of Solid-State Circuits, vol. 40, pp. 2766-2776, December 2005, IEEE, New York, N.Y.